System for use in treatment of vertebral fractures

ABSTRACT

Methods and devices that displace bone or other hard tissue to create a cavity in the tissue. Where such methods and devices rely on a driving mechanism for providing moving of the device to form a profile that improves displacement of the tissue. These methods and devices also allow for creating a path or cavity in bone for insertion of bone cement or other filler to treat a fracture or other condition in the bone. The features relating to the methods and devices described herein can be applied in any region of bone or hard tissue where the tissue or bone is displaced to define a bore or cavity instead of being extracted from the body such as during a drilling or ablation procedure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/157,402 filed Jan. 16, 2014, which is a continuation of U.S.application Ser. No. 12/571,174 filed Sep. 30, 2009, which claimsbenefit of priority to U.S. Provisional Application Nos. 61/194,766filed Sep. 30, 2008 and 61/104,380 filed Oct. 10, 2008, the entirety ofeach of which is incorporated by reference.

FIELD OF THE INVENTION

This invention relates to medical instruments and systems for creating apath or cavity in vertebral bone to receive bone cement to treat avertebral compression fracture. The features relating to the methods anddevices described herein can be applied in any region of bone or hardtissue where the tissue or bone is displaced to define a bore or cavityinstead of being extracted from the body such as during a drilling orablation procedure.

SUMMARY OF THE INVENTION

Methods and devices described herein relate to improved creation of acavity within bone or other hard tissue where the cavity is created bydisplacement of the tissue. In a first example, a method according, tothe present disclosure includes treating a vertebral body or other bonestructure. In one variation, the method includes providing an elongatetool having a sharp tip configured for penetration into vertebral bone,the tool having an axis extending from a proximal end to a working endthereof, where the working end comprises at least a first sleeveconcentrically located within a second sleeve and a third sleeve locatedconcentrically about the second sleeve, where each sleeve comprises aseries of slots or notches to limit deflection of the working end to afirst curved configuration in a single plane and where the respectiveseries of slots or notches are radially offset in each sleeve; advancingthe working end through vertebral bone; causing the working end to movefrom a linear configuration to a curved configuration by translating thefirst sleeve relative to the second sleeve in an axial direction; andmoving the working end in the curved configuration within the bone tocreate a cavity therein. Translating of the first sleeve relative to thesecond sleeve can include moving either sleeve or both sleeves in anaxial direction. Additional variations include moving one or bothsleeves in a rotational direction to produce relative axial displacementbetween sleeves.

In variations of the method, moving the working end to from the linearconfiguration to the curved configuration can include moving the workingend to move through a plurality of curved configurations.

In an additional variation, causing the working end to move from alinear configuration to the curved configuration comprises actuating ahandle mechanism to move the working end from the linear configurationto the curved configuration. The handle mechanism can be moved axiallyand/or rotationally as described herein.

In one variation, actuating of the handle mechanism causes the workingend to move to the first curved configuration without torquing the thirdsleeve.

In additional variations, the working end of the osteotome or tool isspring biased to assume the linear configuration.

The working end can move from the linear configuration to the curvedconfiguration by applying a driving force or impact to the elongate toolwherein penetration in the cortical bone moves the working end from thelinear configuration to the curved configuration. For example, as ahammering or impact force is applied to the working end, the interactionof the sharp tip against bone causes the working end to assume anarticulated and/or curved configuration. Where further axial movement ofthe tool causes compression of the bone and creation of the cavity.

The method can further include the use of one or more cannulae tointroduce the tool into the target region. Such a cannula can maintainthe tool in a straight or linear configuration until the tool advancesout of the cannula or until the cannula is withdrawn from over the tool.

As described herein, upon creation of the cavity, the method can furtherinclude the insertion of a filler material or other substance into thecavity. The filler material can be delivered through the tool or througha separate cannula or catheter.

This disclosure also includes variations of devices for creating acavity within bone or hard tissue. Such variations include devices fortreating a vertebral body or other such structure. In one variation adevice includes a handle having an actuating portion; a shaft comprisinga first sleeve located concentrically within a second sleeve and a thirdsleeve located concentrically about the second sleeve, the shaft havinga distal portion comprising a working end capable of moving between alinear configuration and an articulated configuration where the secondarticulated configuration is limited to a single plane, and where eachsleeve comprises a series of slots or notches to limit deflection of theworking end to the articulated configuration, where the respectiveseries of slots or notches are radially offset in each sleeve; and asharp tip located at a distal tip of the working end, the sharp tipadapted to penetrate vertebral bone within the vertebral body.

In one variation, the devices described herein can include aconfiguration where the first sleeve is affixed to the second sleeve atthe working end such that proximal movement of the first sleeve causesthe working end to assume the articulated configuration. The sleeves canbe affixed at any portion along their length via a mechanical fixationmeans (e.g., a pin or other fixation means), an adhesive, or one or moreweld points. In some variations, fixation of the sleeves occurs at theworking end so that movement of the inner or first sleeve causes theworking end to assume the curved configuration. In some cases, the thirdsleeve can be affixed outside of the working end so long as when thefirst and second sleeves articulate, the third sleeve still articulates.

Devices described herein can optionally include a force-limitingassembly coupled between the actuating portion and the first sleeve suchthat upon reaching a threshold force, the actuating portion disengagesthe first sleeve. In one variation, the force-limiting mechanism isadapted to limit force applied to bone when moving the working end fromthe first configuration toward the second configuration.

In additional variations, devices for creating cavities in bone or hardtissue can include one or more spring elements that extending throughthe first sleeve, where the spring element is affixed to the shaft(within or about either the first, second, or third sleeve). Such springelements cause the working end to assume a linear configuration in arelaxed state.

In additional variations, a device can include an outer or third sleevewhere the slots or notches (that allow deflection) are located on anexterior surface of the third sleeve. The exterior surface is typicallythe surface that faces outward from a direction of the curvedconfiguration. This configuration allows for an interior surface (thesurface located on the interior of the curved portion) to be smooth. Asa result, if the device is withdrawn through tissue or a cannula orother introducer, the smooth surface on the interior of the curveminimizes the chance that the device becomes caught on the opening ofthe cannula or any other structure.

Variations of the device can include one or more lumens that extendthrough the shaft and working end. These lumens can exit at a distal tipof the device or through a side opening in a wall of the device. Thelumen can include a surface comprising a lubricious polymeric material.For example, the material can comprise any bio-compatible materialhaving low frictional properties (e.g., TEFLON®, apolytetrafluroethylene (PTFE), FEP (Fluorinated ethylenepropylene),polyethylene, polyamide, ECTFE (Ethylenechlorotrifluoro-ethylene), ETFE,PVDF, polyvinyl chloride and silicone).

As described herein, the devices can include any number ofconfigurations to prevent rotation between adjacent sleeves but allowaxial movement between the sleeves. For example, the sleeves can bemechanically coupled via a pin/slot or key/keyway configuration. In anadditional variation, the sleeves can be non-circular to preventrotation.

In an additional variation, the disclosure includes various kitscomprising the device described herein as well as a filler material(e.g., a bone cement or other bone filler material).

Variations of the access device and procedures described above includecombinations of features of the various embodiments or combination ofthe embodiments themselves wherever possible.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view of an osteotome of the invention.

FIG. 2 is a side view of the osteotome of FIG. 1.

FIG. 3 is a cross sectional view of the osteotome of FIG. 1.

FIG. 4 is an enlarged sectional view of the handle of the osteotome ofFIG. 1.

FIG. 5 is an enlarged sectional view of the working end of the osteotomeof FIG. 1.

FIG. 6A is a sectional view of the working end of FIG. 5 in a linearconfiguration.

FIG. 6B is a sectional view of the working end of FIG. 5 in a curvedconfiguration.

FIGS. 7A-7C are schematic sectional views of a method of use of theosteotome of FIG. 1.

FIG. 8 is another embodiment of an osteotome working end.

FIG. 9 is another embodiment of an osteotome working end.

FIG. 10 is another variation of an osteotome with an outer sleeve.

FIG. 11 is a cut-away view of the working end of the osteotome of FIG.10.

FIG. 12A is sectional view of another embodiment of working end, takenalong line 12A-12A of FIG. 11.

FIGS. 12B and 12C illustrate additional variations of preventingrotation between adjacent sleeves.

FIG. 13 is sectional view of another working end embodiment similar tothat of FIG. 11.

FIG. 14 is a cut-away perspective view of the working end of FIG. 13.

DETAILED DESCRIPTION

Referring to FIGS. 1-5, an apparatus or osteotome 100 is shown that isconfigured for accessing the interior of a vertebral body and forcreating a pathway in vertebral cancellous bone to receive bone cement.In one embodiment, the apparatus is configured with an extension portionor member 105 for introducing through a pedicle and wherein a workingend 110 of the extension member can be progressively actuated to curve aselected degree and/or rotated to create a curved pathway and cavity inthe direction of the midline of the vertebral body. The apparatus can bewithdrawn and bone fill material can be introduced through a bone cementinjection cannula. Alternatively, the apparatus 100 itself can be usedas a cement injector with the subsequent injection of cement through alumen 112 of the apparatus.

In one embodiment, the apparatus 100 comprises a handle 115 that iscoupled to a proximal end of the extension member 105. The extensionmember 105 comprises an assembly of first (outer) sleeve 120 and asecond (inner) sleeve 122, with the first sleeve 120 having a proximalend 124 and distal end 126. The second sleeve 122 has a proximal end 134and distal end 136. The extension member 105 is coupled to the handle115, as will be described below, to allow a physician to drive theextension member 105 into bone while contemporaneously actuating theworking end 110 into an actuated or curved configuration (see FIG. 6).The handle 115 can be fabricated of a polymer, metal or any othermaterial suitable to withstand hammering or impact forces used to drivethe assembly into bone (e.g., via use of a hammer or similar device onthe handle 115). The inner and outer sleeves are fabricated of asuitable metal alloy, such as stainless steel or NiTi. The wallthicknesses of the inner and outer sleeves can range from about 0.005″to 0.010″ with the outer diameter the outer sleeve ranging from about2.5 mm to 5.0 mm.

Referring to FIGS. 1, 3 and 4, the handle 115 comprises both a firstgrip portion 140 and a second actuator portion indicated at 142. Thegrip portion 140 is coupled to the first sleeve 120 as will be describedbelow. The actuator portion 142 is operatively coupled to the secondsleeve 122 as will be described below. The actuator portion 142 isrotatable relative to the grip portion 140 and one or more plastic flextabs 145 of the grip portion 140 are configured to engage notches 146 inthe rotatable actuator portion 142 to provide tactile indication andtemporary locking of the handle portions 140 and 142 in a certain degreeof rotation. The flex tabs 145 thus engage and disengage with thenotches 146 to permit ratcheting (rotation and locking) of the handleportions and the respective sleeve coupled thereto.

The notches or slots in any of the sleeves can comprise a uniform widthalong. the length of the working end or can comprise a varying width.Alternatively, the width can be selected in certain areas to effectuatea particular curved profile. In other variation, the width can increaseor decrease along the working end to create a curve having a varyingradius. Clearly, it is understood that any number of variations arewithin the scope of this disclosure.

FIG. 4 is a sectional view of the handle showing a mechanism foractuating the second inner sleeve 122 relative to the first outer sleeve120. The actuator portion 142 of the handle 115 is configured with afast-lead helical groove indicated at 150 that cooperates with aprotruding thread 149 of the grip portion 140 of the handle. Thus, itcan be understood that rotation of the actuation portion 142 will movethis portion to the position indicated at 150 (phantom view). In oneembodiment, when the actuator portion 142 is rotated a selected amountfrom about 45° to 720°, or from about 90° to 360°, the inner sleeve 122is lifted proximally relative to the grip portion 140 and outer sleeve120 to actuate the working end 110. As can be seen in FIG. 4 theactuator portion 142 engages flange 152 that is welded to the proximalend 132 of inner sleeve 122. The flange 152 is lifted by means of a ballbearing assembly 154 disposed between the flange 152 and metal bearingsurface 155 inserted into the grip portion 140 of the handle. Thus, therotation of actuator 142 can lift the inner sleeve 122 without creatingtorque on the inner sleeve.

Now turning to FIGS. 5, 6A and 6B, it can be seen that the working end110 of the extension member 105 is articulated by cooperating slottedportions of the distal portions of outer sleeve 120 and inner sleeve 122that are both thus capable of bending in a substantially tight radius.The outer sleeve 120 has a plurality of slots or notches 162 thereinthat can be any slots that are perpendicular or angled relative to theaxis of the sleeve. The inner sleeve 122 has a plurality of slots ornotches indicated at 164 that can be on an opposite side of the assemblyrelative to the slots 162 in the outer sleeve 120. The outer and innersleeves are welded together at the distal region indicated at weld 160.It thus can be understood that when inner sleeve 122 is translated inthe proximal direction, the outer sleeve will be flexed as depicted inFIG. 6B. It can be understood that by rotating the actuator handleportion 142 a selected amount, the working end can be articulated to aselected degree.

FIG. 4, 5, 6A and 6B further illustrate another element of the apparatusthat comprises a flexible flat wire member 170 with a proximal end 171and flange 172 that is engages the proximal side of flange 152 of theinner sleeve 122. At least the distal portion 174 of the flat wiremember 170 is welded to the inner sleeve at weld 175. This flat wiremember thus provides a safety feature to retain the working end in theevent that the inner sleeve fails at one of the slots 164.

Another safety feature of the apparatus comprises a torque limiter andrelease system that allows the entire handle assembly 115 to freelyrotate—for example if the working end 110 is articulated, as in FIG. 6B,when the physician rotates the handle and when the working end isengaged in strong cancellous bone. Referring to FIG. 4, the grip portion142 of the handle 115 engages a collar 180 that is fixed to a proximalend 124 of the outer sleeve 120. The collar 180 further comprisesnotches 185 that are radially spaced about the collar and are engaged bya ball member 186 that is pushed by a spring 188 into notches 185. At aselected force, for example a torque ranging from greater than about 0.5inch*lbs but less that about 7.5 inch*lbs, 5.0 inch*lbs or 2.5 inch*lbs,the rotation of the handle 115 overcomes the predetermined limit. Whenthe torque limiter assembly is in its locked position, the ball bearing186 is forced into one of the notches 185 in the collar 180. When toomuch torque is provided to the handle and outer sleeve, the ball bearing186 disengages the notch 185 allowing the collar 180 to turn, and thenreengages at the next notch, releasing anywhere from 0.5 inch*lbs to 7.5inch*lbs of torque.

Referring to FIGS. 6A and 6B, it can be understood that the inner sleeve122 is weakened on one side at its distal portion so as to permit theinner sleeve 122 to bend in either direction but is limited by thelocation of the notches in the outer sleeve 120. The curvature of anyarticulated configuration is controlled by the spacing of the notches aswell as the distance between each notch peak. The inner sleeve 122 alsohas a beveled tip for entry through the cortical bone of a vertebralbody. Either the inner sleeve or outer sleeve can form the distal tip.

Referring to FIGS. 7A-7C, in one variation of use of the device, aphysician taps or otherwise drives a stylet 200 and introducer sleeve205 into a vertebral body 206 typically until the stylet tip 208 iswithin the anterior ⅓ of the vertebral body toward cortical bone 210(FIG. 7A). Thereafter, the stylet 200 is removed and the sleeve 205 ismoved proximally (FIG. 7B). As can be seen in FIG. 7B, the tool orosteotome 100 is inserted through the introducer sleeve 205 andarticulated in a series of steps as described above. The working end 110can be articulated intermittently while applying driving forces andoptionally rotational forces to the handle 115 to advance the workingend through the cancellous bone 212 to create path or cavity 215. Thetool is then tapped to further drive the working end 110 to, toward orpast the midline of the vertebra. The physician can alternativelyarticulate the working end 110, and drive and rotate the working endfurther until imaging shows that the working end 100 has created acavity 215 of an optimal configuration. Thereafter, as depicted in FIG.7C, the physician reverses the sequence and progressively straightensthe working end 110 as the extension member is withdrawn from thevertebral body 206. Thereafter, the physician can insert a bone cementinjector 220 into the path or cavity 215 created by osteotome 100. FIG.7C illustrates a bone cement 222, for example a PMMA cement, beinginjected from a bone cement source 225.

In another embodiment (not shown), the apparatus 100 can have a handle115 with a Luer fitting for coupling a bone cement syringe and the bonecement can be injected through the lumen 112 of the apparatus. In suchan embodiment FIG. 9, the lumen can have a lubricious surface layer orpolymeric lining 250 to insure least resistance to bone cement as itflows through the lumen. In one embodiment, the surface or lining 250can be a fluorinated polymer such as TEFLON® or polytetrafluroethylene(PTFE). Other suitable fluoropolymer resins can be used such as FEP andPFA. Other materials also can be used such as FEP (Fluorinatedethylenepropylene), ECTFE (Ethylenechlorotrifluoro-ethylene), ETFE,Polyethylene, Polyamide, PVDF, Polyvinyl chloride and silicone. Thescope of the invention can include providing a polymeric material havinga static coefficient of friction of less than 0.5, less than 0.2 or lessthan 0.1.

FIG. 9 also shows the extension member or shaft 105 can be configuredwith an exterior flexible sleeve indicated at 255. The flexible sleevecan be any commonly known biocompatible material, for example, thesleeve can comprise any of the materials described in the precedingparagraph.

As also can be seen in FIG. 9, in one variation of the device 100, theworking end 110 can be configured to deflect over a length indicated at260 in a substantially smooth curve. The degree of articulation of theworking end 100 can be at least 45°, 90°, 135° or at least 180° asindicated at 265 (FIG. 9). In additional variations, the slots of theouter 120 and inner sleeves 120 can be varied to produce a device havinga radius of curvature that varies among the length 260 of the device100.

In another embodiment of the invention, the inner sleeve can be springloaded relative the outer sleeve, in such a way as to allow the workingend to straighten under a selected level of force when pulled in alinear direction. This feature allows the physician to withdraw theassembly from the vertebral body partly or completely without furtherrotation the actuating portion 142 of handle 115. In some variations,the force-limiter can be provided to allow less than about 10 inch*lbsof force to be applied to bone.

In another embodiment shown in FIG. 8, the working end 110 is configuredwith a tip 240 that deflects to the position indicated at 240′ whendriven into bone. The tip 240 is coupled to the sleeve assembly byresilient member 242, for example a flexible metal such as stainlesssteel or NiTi. It has been found that the flexing of the tip 240 causesits distal surface area to engage cancellous bone which can assist indeflecting the working end 110 as it is hammered into bone.

In another embodiment of the invention (not shown), the actuator handlecan include a secondary (or optional) mechanism for actuating theworking end. The mechanism would include a hammer-able member with aratchet such that each tap of the hammer would advance assembly andprogressively actuate the working end into a curved configuration. Aratchet mechanism as known in the art would maintain the assembly ineach of a plurality of articulated configurations. A release would beprovided to allow for release of the ratchet to provide forstraightening the extension member 105 for withdrawal from the vertebralbody.

FIGS. 10 and 11 illustrate another variation of a bone treatment device400 with a handle 402 and extension member 405 extending to working end410 having a similar construction to that FIGS. 1 to 6B. The device 400operates as described previously with notched first (outer) sleeve 120and cooperating notched second (inner) sleeve 122. However, thevariation shown in FIGS. 10 and 11 also includes a third concentricnotched sleeve 420, exterior to the first 120 and second 122 sleeves.The notches or slots in sleeve 420 at the working end 410 permitdeflection of the sleeve as indicated at 265 in FIG. 11.

FIG. 10 also illustrates the treatment device 400 as including a luerfitting 412 that allows the device 402 to be coupled to a source of afiller material (e.g., a bone filler or bone cement material). The luercan be removable from the handle 402 to allow application of an impactforce on the handle as described above. Moreover, the luer fitting 402can be located on the actuating portion of the handle, the stationarypart of the handle or even along the sleeve. In any case, variations ofthe device 400 permit coupling the filler material with a lumenextending through the sleeves (or between adjacent sleeves) to depositfiller material at the working end 410. As shown by arrows 416, fillermaterial can be deposited through a distal end of the sleeves (where thesharp tip is solid) or can be deposited through openings in a side-wallof the sleeves. Clearly, variations of this configuration are within thescope of those familiar in the field.

In some variations, the third notched sleeve 420 is configured with itssmooth (non-notched) surface 424 disposed to face inwardly on thearticulated working end (FIG. 11) such that a solid surface forms theinterior of the curved portion of the working end 410. The smoothsurface 424 allows withdrawal of the device 110 into a cannula orintroducer 205 without creating a risk that the slots or notches becomecaught on a cannula 205 (see e.g., FIG. 7B).

As shown in FIGS. 10-11, the third (outermost) sleeve 420 can extendfrom an intermediate location on the extension member 405 to a distalend of the working end 410. However, variations of the device includethe third sleeve 420 extending to the handle 402. However, the thirdsleeve 420 is typically not coupled to the handle 402 so that anyrotational force or torque generated by the handle 402 is not directlytransmitted to the third sleeve 420.

In one variation, the third sleeve 420 is coupled to the second sleeve120 at only one axial location. In the illustrated example shown in FIG.11, the third sleeve 420 is affixed to second sleeve 420 by welds 428 atthe distal end of the working end 410. However, the welds or otherattachment means (e.g., a pin, key/keyway, protrusion, etc.) can belocated on a medial part of the sleeve 420. The sleeve 420 can befabricated of any bio-compatible material. For example, in onevariation, the third sleeve is fabricated form a 3.00 mm diameterstainless steel material with a wall thickness of 0.007″. The first,second and third sleeves are sized to have dimensions to allow a slidingfit between the sleeves.

FIG. 12A is a sectional view of extension member 405 of anothervariation, similar to that shown in FIGS. 10-11. However, the variationdepicted by FIG. 12A comprises non-round configurations of concentricslidable sleeves (double or triple sleeve devices). This configurationlimits or prevents rotation between the sleeves and allows the physicianto apply greater forces to the bone to create a cavity. While FIG. 12Aillustrates an oval configuration, any non-round shape is within thescope of this disclosure. For example, the cross-sectional shape cancomprise a square, polygonal, or other radially keyed configuration asshown in FIGS. 12B and 12C. As shown in FIG. 12C the sleeves can includea key 407 and a receiving keyway 409 to prevent rotation but allowrelative or axial sliding of the sleeves. The key can comprise anyprotrusion or member that slides within a receiving keyway. Furthermore,the key can comprise a pin or any raised protrusion on an exterior orinterior of a respective sleeve. In this illustration, only the first122 and second 120 sleeves are illustrated. However, any of the sleevescan be configured with the key/keyway. Preventing rotation betweensleeves improves the ability to apply force to bone at the articulatedworking end.

FIGS. 13-14 illustrate another variation of a working end 410 of anosteotome device. In this variation, the working end 410 includes one ormore flat spring elements 450, 460 a, 460 b, 460 c, 460 d, that preventrelative rotation of the sleeves of the assembly thus allowing greaterrotational forces to be applied to cancellous bone from an articulatedworking end. The spring elements further urge the working end assemblyinto a linear configuration. To articulate the sleeves, a rotationalforce is applied to the handle as described above, once this rotationalforce is removed, the spring elements urge the working end into a linearconfiguration. As shown in FIG. 13, one or more of the spring elementscan extend through the sleeves for affixing to a handle to preventrotation. Furthermore, the distal end 454 of flat spring element 450 isfixed to sleeve assembly by weld 455. Thus, the spring element is fixedat each end to prevent its rotation. Alternate variations include one ormore spring elements being affixed to the inner sleeve assembly at amedial section of the sleeve.

As shown in FIGS. 13-14, variations of the osteotome can include anynumber of spring elements 460 a-460 d. These additional spring elements460 a-460 d can be welded at either a proximal or distal end thereof toan adjacent element or a sleeve to allow the element to function as aleaf spring.

Although particular embodiments of the present invention have beendescribed above in detail, it will be understood that this descriptionis merely for purposes of illustration and the above description of theinvention is not exhaustive. Specific features of the invention areshown in some drawings and not in others, and this is for convenienceonly and any feature may be combined with another in accordance with theinvention. A number of variations and alternatives will be apparent toone having ordinary skills in the art. Such alternatives and variationsare intended to be included within the scope of the claims. Particularfeatures that are presented in dependent claims can be combined and fallwithin the scope of the invention. The invention also encompassesembodiments as if dependent claims were alternatively written in amultiple dependent claim format with reference to other independentclaims.

What is claimed is:
 1. A medical device for treating a hard tissue,comprising: a handle having an actuating portion mechanically coupled toa working end of a shaft; the shaft comprising a first sleeve locatedconcentrically within a second sleeve and a third sleeve locatedconcentrically about the second sleeve, the shaft having a distalportion comprising the working end capable of moving reversibly betweena linear configuration and an articulated configuration in response tomovement of the actuating portion, where the articulated configurationis limited to a single plane, and where each sleeve comprises a seriesof slots or notches to limit deflection of the working end to thearticulated configuration, where the respective series of slots ornotches are radially offset in adjacent sleeves; wherein the actuatingportion is temporarily lockable in a certain degree of rotation withrespect to a longitudinal axis of the shaft; and a sharp tip located ata distal tip of the working end, the sharp tip adapted to penetrate hardtissue and a point of the sharp tip is offset to engage hard tissue whenadvanced therein to assist in deflecting the working end.
 2. The medicaldevice of claim 1, where the first sleeve is affixed to the secondsleeve at the working end such that relative axial movement of the firstand second sleeves causes the working end to assume the articulatedconfiguration.
 3. The medical device of claim 1, where the second sleeveis affixed to the third sleeve at the working end.
 4. The medical deviceof claim 1, further comprising a force-limiting assembly coupled betweenthe actuating portion and the first sleeve such that upon reaching athreshold force, the actuating portion disengages the first sleeve. 5.The medical device of claim 1, further comprising at least one springelement extending through the first sleeve, where the spring element isaffixed to the shaft and causes the working end to assume the linearconfiguration in a relaxed state.
 6. The medical device of claim 1,wherein the second configuration comprises a plurality of articulatedconfigurations.
 7. The medical device of claim 1, where the third sleeveends at an intermediate portion of the tool to limit torque orrotational forces generated by the handle mechanism.
 8. The medicaldevice of claim 1, where the third sleeve extends to the handle portion.9. The medical device of claim 1, where the slots or notches on thethird sleeve are located on an exterior side of the third sleeve thatfaces outward from a direction of the curved configuration such that aninterior side of the curved configuration is solid.
 10. The medicaldevice of claim 1, wherein the first sleeve is coupled to the actuationportion of the handle such that rotation of the actuation portion of thehandle causes axial movement of the first sleeve to deform the workingend into the articulated configuration.
 11. The medical device of claim1, where the handle is configured to receive an impact force, and whereresistance of the sharp tip against bone causes the working end toassume the curved configuration.
 12. The medical device of claim 1,further comprising a lumen extending through the shaft and working end.13. The medical device of claim 12, where wherein the sharp tip is solidand where the lumen terminated proximal to the sharp tip.
 14. Themedical device of claim 12, further comprising a source of a bone cementmaterial that is fluidly coupled to lumen the bone cement material canpass through the lumen to exit at the working end.
 15. The medicaldevice of claim 14, wherein the lumen terminates in a side opening in awall of the shaft such that bone cement material exits proximal to thedistal tip.
 16. The medical device of claim 12, wherein the lumenincludes a surface comprising a lubricous polymeric material.
 17. Themedical device of claim 1, where the first, second and third sleeves areprevented from rotating with respect to one another.
 18. A kitcomprising: a medical device comprising: a handle having an actuatingportion; a shaft comprising a first sleeve located concentrically withina second sleeve and a third sleeve located concentrically about thesecond sleeve, the shaft having a distal portion comprising a workingend capable of moving reversibly between a linear configuration and anarticulated configuration where the articulated configuration is limitedto a single plane, and where each sleeve comprises a series of slots ornotches to limit deflection of the working end to the articulatedconfiguration, where the respective series of slots or notches areradially offset in adjacent sleeves; wherein the actuating portion isreleasably lockable a certain degree of rotation with respect to alongitudinal axis of the shaft; and a sharp tip located at a distal tipof the working end, the sharp tip adapted to penetrate hard tissue and apoint of the sharp tip is offset to engage hard tissue when advancedtherein to assist in deflecting the working; and a bone filler material.